OpenRaiser/Intern-Atlas huggingface dataset:
Estimated Depth Map Helps Image Classification
Venue: arXiv cs.CV 2017
Year: 2017

We consider image classification with estimated depth. This problem falls into the domain of transfer learning, since we are using a model trained on a set of depth images to generate depth maps (additional features) for use in another classification problem using another disjoint set of images. It's challenging as no direct depth information is provided. Though depth estimation has been well studied, none have attempted to aid image classification with estimated depth. Therefore, we present a way of transferring domain knowledge on depth estimation to a separate image classification task over a disjoint set of train, and test data. We build a RGBD dataset based on RGB dataset and do image classification on it. Then evaluation the performance of neural networks on the RGBD dataset compared to the RGB dataset. From our experiments, the benefit is significant with shallow and deep networks. It improves ResNet-20 by 0.55% and ResNet-56 by 0.53%. Our code and dataset are available publicly.
On the Use of Machine Translation-Based Approaches for Vietnamese Diacritic Restoration
Venue: arXiv cs.CL 2017
Year: 2017

This paper presents an empirical study of two machine translation-based approaches for Vietnamese diacritic restoration problem, including phrase-based and neural-based machine translation models. This is the first work that applies neural-based machine translation method to this problem and gives a thorough comparison to the phrase-based machine translation method which is the current state-of-the-art method for this problem. On a large dataset, the phrase-based approach has an accuracy of 97.32% while that of the neural-based approach is 96.15%. While the neural-based method has a slightly lower accuracy, it is about twice faster than the phrase-based method in terms of inference speed. Moreover, neural-based machine translation method has much room for future improvement such as incorporating pre-trained word embeddings and collecting more training data.
Modeling and Quantifying the Forces Driving Online Video Popularity Evolution
Venue: arXiv cs.SI 2017
Year: 2017

Video popularity is an essential reference for optimizing resource allocation and video recommendation in online video services. However, there is still no convincing model that can accurately depict a video's popularity evolution. In this paper, we propose a dynamic popularity model by modeling the video information diffusion process driven by various forms of recommendation. Through fitting the model with real traces collected from a practical system, we can quantify the strengths of the recommendation forces. Such quantification can lead to characterizing video popularity patterns, user behaviors and recommendation strategies, which is illustrated by a case study of TV episodes.
Learning RBM with a DC programming Approach
Venue: arXiv cs.LG 2017
Year: 2017

By exploiting the property that the RBM log-likelihood function is the difference of convex functions, we formulate a stochastic variant of the difference of convex functions (DC) programming to minimize the negative log-likelihood. Interestingly, the traditional contrastive divergence algorithm is a special case of the above formulation and the hyperparameters of the two algorithms can be chosen such that the amount of computation per mini-batch is identical. We show that for a given computational budget the proposed algorithm almost always reaches a higher log-likelihood more rapidly, compared to the standard contrastive divergence algorithm. Further, we modify this algorithm to use the centered gradients and show that it is more efficient and effective compared to the standard centered gradient algorithm on benchmark datasets.
Analysis of Wireless-Powered Device-to-Device Communications with Ambient Backscattering
Venue: arXiv cs.NI 2017
Year: 2017

Self-sustainable communications based on advanced energy harvesting technologies have been under rapid development, which facilitate autonomous operation and energy-efficient transmission. Recently, ambient backscattering that leverages existing RF signal resources in the air has been invented to empower data communication among low-power devices. In this paper, we introduce hybrid device-to-device (D2D) communications by integrating ambient backscattering and wireless-powered communications. The hybrid D2D communications are self-sustainable, as no dedicated external power supply is required. However, since the radio signals for energy harvesting and backscattering come from external RF sources, the performance of the hybrid D2D communications needs to be optimized efficiently. As such, we design two mode selection protocols for the hybrid D2D transmitter, allowing a more flexible adaptation to the environment. We then introduce analytical models to characterize the impacts of the considered environment factors, e.g., distribution, spatial density, and transmission load of the ambient transmitters, on the hybrid D2D communications performance. Extensive simulations show that the repulsion factor among the ambient transmitters has a non-trivial impact on the communication performance. Additionally, we reveal how different mode selection protocols affect the performance metrics.
A spatial scientometric analysis of the publication output of cities worldwide
Venue: arXiv cs.DL 2017
Year: 2017

In tandem with the rapid globalisation of science, spatial scientometrics has become an important research sub-field in scientometric studies. Recently, numerous spatial scientometric contributions have focused on the examination of cities' scientific output by using various scientometric indicators. In this paper, I analyse cities' scientific output worldwide in terms of the number of journal articles indexed by the Scopus database, in the period from 1986 to 2015. Furthermore, I examine which countries are the most important collaborators of cities. Finally, I identify the most productive disciplines in each city. I use GPS Visualizer to illustrate the scientometric data of nearly 2,200 cities on maps. Results show that cities with the highest scientific output are mostly located in developed countries and China. Between 1986 and 2015, the greatest number of scientific articles were created in Beijing. The international hegemony of the United States in science has been described by many studies, and is also reinforced by the fact that the United States is the most important collaborator to more than 75 percent of all cities. Medicine is the most productive discipline in two-thirds of cities. Furthermore, cities having the highest scientific output in specific disciplines show well-defined geographical patterns.
Neural network identification of people hidden from view with a single-pixel, single-photon detector
Venue: arXiv cs.CV 2017
Year: 2017

Light scattered from multiple surfaces can be used to retrieve information of hidden environments. However, full three-dimensional retrieval of an object hidden from view by a wall has only been achieved with scanning systems and requires intensive computational processing of the retrieved data. Here we use a non-scanning, single-photon single-pixel detector in combination with an artificial neural network: this allows us to locate the position and to also simultaneously provide the actual identity of a hidden person, chosen from a database of people (N=3). Artificial neural networks applied to specific computational imaging problems can therefore enable novel imaging capabilities with hugely simplified hardware and processing times
Real-time predictive maintenance for wind turbines using Big Data frameworks
Venue: arXiv cs.DC 2017
Year: 2017

This work presents the evolution of a solution for predictive maintenance to a Big Data environment. The proposed adaptation aims for predicting failures on wind turbines using a data-driven solution deployed in the cloud and which is composed by three main modules. (i) A predictive model generator which generates predictive models for each monitored wind turbine by means of Random Forest algorithm. (ii) A monitoring agent that makes predictions every 10 minutes about failures in wind turbines during the next hour. Finally, (iii) a dashboard where given predictions can be visualized. To implement the solution Apache Spark, Apache Kafka, Apache Mesos and HDFS have been used. Therefore, we have improved the previous work in terms of data process speed, scalability and automation. In addition, we have provided fault-tolerant functionality with a centralized access point from where the status of all the wind turbines of a company localized all over the world can be monitored, reducing O&M costs.
Geometric SMOTE: Effective oversampling for imbalanced learning through a geometric extension of SMOTE
Venue: arXiv cs.LG 2017
Year: 2017

Classification of imbalanced datasets is a challenging task for standard algorithms. Although many methods exist to address this problem in different ways, generating artificial data for the minority class is a more general approach compared to algorithmic modifications. SMOTE algorithm and its variations generate synthetic samples along a line segment that joins minority class instances. In this paper we propose Geometric SMOTE (G-SMOTE) as a generalization of the SMOTE data generation mechanism. G-SMOTE generates synthetic samples in a geometric region of the input space, around each selected minority instance. While in the basic configuration this region is a hyper-sphere, G-SMOTE allows its deformation to a hyper-spheroid and finally to a line segment, emulating, in the last case, the SMOTE mechanism. The performance of G-SMOTE is compared against multiple standard oversampling algorithms. We present empirical results that show a significant improvement in the quality of the generated data when G-SMOTE is used as an oversampling algorithm.
Big Data Systems Meet Machine Learning Challenges: Towards Big Data Science as a Service
Venue: arXiv cs.DB 2017
Year: 2017

Recently, we have been witnessing huge advancements in the scale of data we routinely generate and collect in pretty much everything we do, as well as our ability to exploit modern technologies to process, analyze and understand this data. The intersection of these trends is what is called, nowadays, as Big Data Science. Cloud computing represents a practical and cost-effective solution for supporting Big Data storage, processing and for sophisticated analytics applications. We analyze in details the building blocks of the software stack for supporting big data science as a commodity service for data scientists. We provide various insights about the latest ongoing developments and open challenges in this domain.
Energy-Efficient Wireless Interconnection Framework for Multichip Systems with In-package Memory Stacks
Venue: arXiv cs.AR 2017
Year: 2017

Multichip systems with memory stacks and various processing chips are at the heart of platform based designs such as servers and embedded systems. Full utilization of the benefits of these integrated multichip systems need a seamless, and scalable in-package interconnection framework. However, state-of-the-art inter-chip communication requires long wireline channels which increases energy consumption and latency while decreasing data bandwidth. Here, we propose the design of an energy-efficient, seamless wireless interconnection network for multichip systems. We demonstrate with cycle-accurate simulations that such a design reduces the energy consumption and latency while increasing the bandwidth in comparison to modern multichip integration systems.
ROMANO: A Novel Overlay Lightweight Communication Protocol for Unified Control and Sensing of a Network of Robots
Venue: arXiv cs.RO 2017
Year: 2017

We present the Robotic Overlay coMmunicAtioN prOtocol (ROMANO), a lightweight, application layer overlay communication protocol for a unified sensing and control abstraction of a network of heterogeneous robots mainly consisting of low power, low-compute-capable robots. ROMANO is built to work in conjunction with the well-known MQ Telemetry Transport for Sensor Nodes (MQTT-SN) protocol, a lightweight publish-subscribe communication protocol for the Internet of Things and makes use its concept of "topics" to designate the addition and deletion of communication endpoints by changing the subscriptions of topics at each device. We also develop a portable implementation of ROMANO for low power IEEE 802.15.4 (Zigbee) radios and deployed it on a small testbed of commercially available, low-power, and low-compute-capable robots called Pololu 3pi robots. Based on a thorough analysis of the protocol on the real testbed, as a measure of throughput, we demonstrate that ROMANO can guarantee more than a $99.5\%$ message delivery ratio for a message generation rate up to 200 messages per second. The single hop delays in ROMANO are as low as 20ms with linear dependency on the number of robots connected. These delay numbers concur with typical delays in 802.15.4 networks and suggest that ROMANO does not introduce additional delays. Lastly, we implement four different multi-robot applications to demonstrate the scalability, adaptability, ease of integration, and reliability of ROMANO.
Stochastic Tools for Network Intrusion Detection
Venue: arXiv cs.CR 2017
Year: 2017

With the rapid development of Internet and the sharp increase of network crime, network security has become very important and received a lot of attention. We model security issues as stochastic systems. This allows us to find weaknesses in existing security systems and propose new solutions. Exploring the vulnerabilities of existing security tools can prevent cyber-attacks from taking advantages of the system weaknesses. We propose a hybrid network security scheme including intrusion detection systems (IDSs) and honeypots scattered throughout the network. This combines the advantages of two security technologies. A honeypot is an activity-based network security system, which could be the logical supplement of the passive detection policies used by IDSs. This integration forces us to balance security performance versus cost by scheduling device activities for the proposed system. By formulating the scheduling problem as a decentralized partially observable Markov decision process (DEC-POMDP), decisions are made in a distributed manner at each device without requiring centralized control. The partially observable Markov decision process (POMDP) is a useful choice for controlling stochastic systems. As a combination of two Markov models, POMDPs combine the strength of hidden Markov Model (HMM) (capturing dynamics that depend on unobserved states) and that of Markov decision process (MDP) (taking the decision aspect into account). Decision making under uncertainty is used in many parts of business and science.We use here for security tools.We adopt a high-quality approximation solution for finite-space POMDPs with the average cost criterion, and their extension to DEC-POMDPs. We show how this tool could be used to design a network security framework.
Using Markov Models and Statistics to Learn, Extract, Fuse, and Detect Patterns in Raw Data
Venue: arXiv cs.CR 2017
Year: 2017

Many systems are partially stochastic in nature. We have derived data driven approaches for extracting stochastic state machines (Markov models) directly from observed data. This chapter provides an overview of our approach with numerous practical applications. We have used this approach for inferring shipping patterns, exploiting computer system side-channel information, and detecting botnet activities. For contrast, we include a related data-driven statistical inferencing approach that detects and localizes radiation sources.
Service Providers of the Sharing Economy: Who Joins and Who Benefits?
Venue: arXiv cs.CY 2017
Year: 2017

Many "sharing economy" platforms, such as Uber and Airbnb, have become increasingly popular, providing consumers with more choices and suppliers a chance to make profit. They, however, have also brought about emerging issues regarding regulation, tax obligation, and impact on urban environment, and have generated heated debates from various interest groups. Empirical studies regarding these issues are limited, partly due to the unavailability of relevant data. Here we aim to understand service providers of the sharing economy, investigating who joins and who benefits, using the Airbnb market in the United States as a case study. We link more than 211 thousand Airbnb listings owned by 188 thousand hosts with demographic, socio-economic status (SES), housing, and tourism characteristics. We show that income and education are consistently the two most influential factors that are linked to the joining of Airbnb, regardless of the form of participation or year. Areas with lower median household income, or higher fraction of residents who have Bachelor's and higher degrees, tend to have more hosts. However, when considering the performance of listings, as measured by number of newly received reviews, we find that income has a positive effect for entire-home listings; listings located in areas with higher median household income tend to have more new reviews. Our findings demonstrate empirically that the disadvantage of SES-disadvantaged areas and the advantage of SES-advantaged areas may be present in the sharing economy.
Happy Travelers Take Big Pictures: A Psychological Study with Machine Learning and Big Data
Venue: arXiv cs.CV 2017
Year: 2017

In psychology, theory-driven researches are usually conducted with extensive laboratory experiments, yet rarely tested or disproved with big data. In this paper, we make use of 418K travel photos with traveler ratings to test the influential "broaden-and-build" theory, that suggests positive emotions broaden one's visual attention. The core hypothesis examined in this study is that positive emotion is associated with a wider attention, hence highly-rated sites would trigger wide-angle photographs. By analyzing travel photos, we find a strong correlation between a preference for wide-angle photos and the high rating of tourist sites on TripAdvisor. We are able to carry out this analysis through the use of deep learning algorithms to classify the photos into wide and narrow angles, and present this study as an exemplar of how big data and deep learning can be used to test laboratory findings in the wild.
Demography-based Facial Retouching Detection using Subclass Supervised Sparse Autoencoder
Venue: arXiv cs.CV 2017
Year: 2017

Digital retouching of face images is becoming more widespread due to the introduction of software packages that automate the task. Several researchers have introduced algorithms to detect whether a face image is original or retouched. However, previous work on this topic has not considered whether or how accuracy of retouching detection varies with the demography of face images. In this paper, we introduce a new Multi-Demographic Retouched Faces (MDRF) dataset, which contains images belonging to two genders, male and female, and three ethnicities, Indian, Chinese, and Caucasian. Further, retouched images are created using two different retouching software packages. The second major contribution of this research is a novel semi-supervised autoencoder incorporating "subclass" information to improve classification. The proposed approach outperforms existing state-of-the-art detection algorithms for the task of generalized retouching detection. Experiments conducted with multiple combinations of ethnicities show that accuracy of retouching detection can vary greatly based on the demographics of the training and testing images.
Chaotic Dynamic S Boxes Based Substitution Approach for Digital Images
Venue: arXiv cs.CR 2017
Year: 2017

In this paper, we propose an image encryption algorithm based on the chaos, substitution boxes, nonlinear transformation in Galois field and Latin square. Initially, the dynamic S boxes are generated using Fisher Yates shuffle method and piece wise linear chaotic map. The algorithm utilizes advantages of keyed Latin square and transformation to substitute highly correlated digital images and yield encrypted image with valued performance. The chaotic behavior is achieved using Logistic map which is used to select one of thousand S boxes and also decides the row and column of selected S box. The selected S box value is transformed using nonlinear transformation. Along with the keyed Latin square generated using a 256 bit external key, used to substitute secretly plain image pixels in cipher block chaining mode. To further strengthen the security of algorithm, round operation are applied to obtain final ciphered image. The experimental results are performed to evaluate algorithm and the anticipated algorithm is compared with a recent encryption scheme. The analyses demonstrate algorithms effectiveness in providing high security to digital media.
Making the leap to a software platform strategy: Issues and challenges
Venue: arXiv cs.SE 2017
Year: 2017

Context: While there are many success stories of achieving high reuse and improved quality using software platforms, there is a need to investigate the issues and challenges organizations face when transitioning to a software platform strategy. Objective: This case study provides a comprehensive taxonomy of the challenges faced when a medium-scale organization decided to adopt software platforms. The study also reveals how new trends in software engineering (i.e. agile methods, distributed development and flat management structures) interplayed with the chosen platform strategy. Method: We used an ethnographic approach to collect data by spending time at a medium-scale company in Scandinavia. We conducted 16 in-depth interviews with representatives of eight different teams, three of which were working on three separate platforms. The collected data was analyzed using Grounded Theory. Results: The findings identify four classes of challenges, namely: business challenges, organizational challenges, technical challenges, and people challenges. The article explains how these findings can be used to help researchers and practitioners identify practical solutions and required tool support. Conclusion: The organization's decision to adopt a software platform strategy introduced a number of challenges. These challenges need to be understood and addressed in order to reap the benefits of reuse. Researchers need to further investigate issues such as supportive organizational structures for platform development, the role of agile methods in software platforms, tool support for testing and continuous integration in the platform context, and reuse recommendation systems.
Female Leadership in Software Projects: A Preliminary Result on Leadership Style and Project Context Factors
Venue: arXiv cs.SE 2017
Year: 2017

Women have been shown to be effective leaders in many team-based situations. However, it is also well-recognized that women are underrepresented in engineering and technology areas, which leads to wasted efforts and a lack of diversity in professional organizations. Although studies about gender and leadership are rich, research focusing on engineering-specific activities, are scarce. To react on this gap, we explored the experience of female leaders of software development projects and possible context factors that influence leadership effectiveness. The study was conducted as a longitudinal multiple case study. Data was collected from survey, interviews, observation and project reports. In this work, we reported some preliminary findings related to leadership style, team perception on leadership and team-task context factors. We found a strong correlation between perceived team leadership and task management. We also observed a potential association between human-oriented leading approach in low customer involvement scenarios and task-oriented leading approach in high customer involvement situations.